1. Field of the Invention
This invention pertains to the field of orthopedic splints and orthoses, and more particularly concerns articulated splints used in physical therapy designed to improve extension of a limb.
2. State of the Prior Art
Orthotic splints are used to assist extension of a joint, typically the knee, elbow or wrist, of a patient for therapeutic reasons. Such splints are well known and commonly used in physical therapy designed to reverse the involuntary contraction of muscles which typically results from protracted disuse of the muscles. This neuromuscular condition is frequent in disabled or comatose patients who are bedridden for long periods of time. The arm, leg and finger muscles become contracted, causing permanent retraction of the elbow, wrist or knee joints. Such a condition can be reversed with physical therapy, by gradually forcing the joints towards an extended condition in small daily increments. After each such extension the involved limb is held at the newly achieved degree of extension by a splint which is attached to the limb and bridges the affected joint. After a number of such sessions the limb may regain a normal range of motion. Splints are also employed in the treatment of other conditions where mobility of a diseased or injured joint must be restricted for therapeutic reasons.
Such splints generally have two end portions, which are fastened to opposite sides of the joint in question by means of straps. The end portions are usually plates curved to fit against the limb surface, and are joined by an intermediate portion which is pliable or flexible to allow bending of the splint to fit the angle of the joint. In its simplest form, a splint has two end plates joined by a narrower midportion which is sufficiently rigid so that the patient is not able to change its shape, yet sufficiently deformable that the therapist can bend it to a desired angle. The splint requires successive adjustment as limb extension progresses, which is also accomplished by bending the semi-rigid intermediate portion of the splint. This simple type of splint merely immobilizes the joint to prevent retraction of the limb.
For some patients, however, it is desirable to allow a limited range of motion of the joint, which may be gradually adjusted and increased as therapy progresses. For this purpose, articulated splints are available which are equipped with a specialized hinge, known as a goniometer. The goniometer has adjustable stops which can be preset by the physical therapist to allow a limited range of motion appropriate to the particular patients needs and condition. in some cases it may be also beneficial to provide a continuous force, as by a spring, urging the limb towards an extended condition to compensate for the greater natural strength of the retractor muscles as compared with extensor muscles and thereby assist the patient in extension of the limb.
Existing articulated splints are of cumbersome design in that the goniometer hinge is in the form of two spaced apart pivots positioned on opposite sides of the joint when the splint is applied to the patient's limb. Range of motion settings must be made on each of the two sides of the goniometer hinge by the therapist. Existing splint goniometers suffer from the additional shortcoming that the range of motion settings are not continuously adjustable, as would be desirable, but only in discrete steps by means of stop pins inserted in a limited number of holes spaced along an arc on the goniometer hinge. Still further, the goniometer hinge on existing splints remains exposed to view on the patient's limb and makes for an awkward looking, aesthetically unappealing apparatus.
What is needed is a splint with a goniometer hinge arrangement which is more compact, easier to adjust, has a continuous range of adjustment, and is less conspicuous when worn by the patient.